Sonoma State University student Rebecca Wilson of Rohnert Park walks along the dam at Spring Lake, Wednesday, January 30, 2013. (Crista Jeremiason / The Press Democrat)

February 2, 2013, 6:08PM

02/02/2013

After drying out from two of the wettest months on record in November and December, Sonoma County residents may have forgotten where they placed their umbrellas in January.

Last month was the seventh-driest January in the last 80 years. While a respite from winter rains is not unusual in January, this stretch has been particularly dry.

"It is not uncommon for there to be a period of dry weather sometime in the December to early February time frame," said Warren Blier, science officer for the National Weather Service in Monterey. "Most years, a period of two weeks or more is common. One year it might be December, one year it might be January or February. It seems to be a regular occurrence."

Especially in the last decade. Of the 10 driest Januaries since 1931, four have occurred within the last 10 years, according to National Weather Service data.

This year, there is neither an El Ni? or La Ni? — the warming or cooling of the ocean at the equator — to influence the weather pattern, Blier said.

In January, Santa Rosa received a mere 1.16 inches of rain, compared to an average of 6.02 inches.

The rainy season began fairly typically in October, with 1.48 inches, which is just below normal. And then things got wet. The county received 8.42 inches of rain in November and 9.75 inches in December, which was well above normal.

Even with dry skies in January, the region has still received more rain than it usually does by this point in the year.

"We are looking at normal. We are slightly above the power curve right now," said Bob Benjamin, a weather service meteorologist. "Santa Rosa is 111 percent of normal and there is still a lot of rain season left to go."

That rain has filled Lake Sonoma and Lake Mendocino, which serve 600,000 customers in Sonoma County and parts of Marin County. Private reservoirs built by growers for agriculture use are also brimming with water.

After drying out from two of the wettest months on record in November and December, Sonoma County residents may have forgotten where they placed their umbrellas in January.

Last month was the seventh-driest January in the last 80 years. While a respite from winter rains is not unusual in January, this stretch has been particularly dry.

"It is not uncommon for there to be a period of dry weather sometime in the December to early February time frame," said Warren Blier, science officer for the National Weather Service in Monterey. "Most years, a period of two weeks or more is common. One year it might be December, one year it might be January or February. It seems to be a regular occurrence."

Especially in the last decade. Of the 10 driest Januaries since 1931, four have occurred within the last 10 years, according to National Weather Service data.

This year, there is neither an El Ni? or La Ni? — the warming or cooling of the ocean at the equator — to influence the weather pattern, Blier said.

In January, Santa Rosa received a mere 1.16 inches of rain, compared to an average of 6.02 inches.

The rainy season began fairly typically in October, with 1.48 inches, which is just below normal. And then things got wet. The county received 8.42 inches of rain in November and 9.75 inches in December, which was well above normal.

Even with dry skies in January, the region has still received more rain than it usually does by this point in the year.

"We are looking at normal. We are slightly above the power curve right now," said Bob Benjamin, a weather service meteorologist. "Santa Rosa is 111 percent of normal and there is still a lot of rain season left to go."

That rain has filled Lake Sonoma and Lake Mendocino, which serve 600,000 customers in Sonoma County and parts of Marin County. Private reservoirs built by growers for agriculture use are also brimming with water.

"Most people have reservoirs for frost protection and irrigation, and they are full," said Nick Frey, president of the Sonoma County Winegrowers. "I don't think it will have much impact on grapes."

The next chance of rain will come on Thursday or Friday, when a typical winter storm is expected to move in, Blier said.